Collapsible chairs are designed with the twin goals of comfort and ease of storage. They are generally collapsed for storage when not in use, so the smaller and more compact the chair can be in its collapsed state, the better it is generally perceived to be by the user. When in use, however, a larger configuration is often desirable, and arm rests are a positive addition to comfort. Some collapsible chairs have used material stretched between frame members to provide arm rests, while others use hard arm members of rigid material such as wood or plastic to provide solid arm rests. These solid arm rests may be perceived as more substantial by users. In particular, when a user raises himself from the chair, it may be more comfortable to have a solid member to push against than a flexible one, when gaining one's footing.
Hard arm folding chairs have been in use for many years. The traditional lawn chair, typically made of aluminum, usually had hard arms, and folded into a flat package by the use of hinges which allowed the frame to move from a rectangular cross-section to a trapezoidal one with the top and bottom edges finally meeting. Variations on this type of chair can be seen in numerous U.S. patents, including U.S. Pat. Nos. 4,536,026, 4,437,700, 4,613,185, 5,855,409, and 6,217,111, to name but a few. These chairs fold in only one direction, either front to back, or side to side. If one were to look at the movement of four feet alone from an overhead perspective, either the front two feet and the rear two feet would approach each other, or the two left side feet would approach the right side feet.
Collapsible chairs have become increasing sophisticated, with a new style that has become increasing popular in recent years. In this style, the chair frame may be made of a number of crossed members making a series of “X”s. When this style of chair is collapsed, the feet move in 2 dimensions toward a central point or area, so that they all move toward each other. This allows the chair to collapse into a compact bundle which is more like an umbrella than the flat package seen in the older style chairs. This style of chair is seen in U.S. Pat. Nos. 5,984,406, and 5,893,605. The difficulty with this type of chair, which will be referred to as an “X-frame chair” is that hard arms are usually attached at 2 points with a swivel or hinge joint. This works well with a chair which collapses in one direction, so that as the left side feet approach the right side feet, the hard arm can move in parallel towards the hard arm on the other side. However, in an X-frame chair, the chair collapses in two directions so that the front left foot approaches the left rear foot at the same time that it approaches the right front foot. A hard arm that is attached by hinge joints at the ends must collapse in length as the hinge joint point move closer to each other. For this reason, the chairs in the two patents referred to above have flexible cloth arms rather than hard arms.
U.S. Pat. No. 6,082,813 discloses an X-frame chair with hard arms, and deals with the problem by having the arms detach at their forward ends from the frame. This however has the disadvantage of leaving the arm members to dangle when the chair is collapsed, so that the members may run into other objects, possibly damaging the members or the other objects. In addition the rear joint may become stressed and break, and there is a small amount of assembly required, which is less desirable than a construction that requires no assembly at all.
Thus there is a need for an X-frame style chair which includes hard arms which are permanently attached, require no assembly, and collapses without detaching the arms in any way.